An electrocoating plant of this kind is known, for example, from DE 103 25 656 B3.
The power supply device of this known electrocoating plant comprises a plurality of power supply units, one pole of which can be selectively connected to one of a plurality of electrode groups and the other pole of which can be connected to one of a plurality of bus bars, which follow one another in the conveying direction of the conveying device. The workpieces are in each case in electrical contact with one of these bus bars while passing through the immersion bath, so that the workpiece lies at the electric potential which is associated with this bus bar. When a workpiece approaches the transition between two consecutive bus bars, these bus bars are connected together in an electrically conductive manner by coupling thyristors.
Due to the division into a plurality of bus bars following one another in the conveying direction, it is possible in the case of this device to apply different output potentials to workpieces passing in succession through the immersion bath if the bus bars are in each case shorter than the distance between two consecutive workpieces. However this means that the workpieces cannot follow one another at any desired short distance.